When choosing a fan, it can be important to understand the pros and cons of different bearing options. This is particularly evident when reviewing the impact on product life. The two main types of bearings found in fans are stainless steel ball bearings or sleeve bearings. Ball bearings are commonly associated with longer operation life, higher temperature ranges, and high reliability. While the life of a fan will last longer with a ball bearing system, these components will increase the cost over their sleeve bearing counterparts. Sleeve bearings are often used in applications that do not require as long of a life and instead want to focus on lower cost. Sleeve bearings do come with some added restrictions when used. Noise can be a major concern in many applications. Sleeve bearings often start with lower noise during early stages of life but will get much noisier later in product life as the grease discharges from the bearing. It is also important to note that fans with sleeve bearings are only recommended for use when mounted in a vertical orientation. Mounting at any other orientation will significantly reduce the product life. To provide the highest quality product possible, Sanyo Denki only uses ball bearings in all of their fans.